Patterns of early visual field loss in open-angle glaucoma.

Area of Science:

• Ophthalmology
• Neuroscience

Background:

• Primary open-angle glaucoma (POAG) is a leading cause of irreversible blindness.
• Early visual field loss patterns in POAG can vary significantly.
• Understanding these patterns may elucidate underlying disease mechanisms.

Purpose of the Study:

• To investigate differences in intraocular pressure and optic disk morphology between POAG patients with distinct early visual field loss patterns.
• To explore potential variations in glaucomatous optic nerve damage mechanisms.

Main Methods:

• Two groups of POAG patients were selected based on visual field criteria: diffuse depression (mean defect > 3.0 dB, loss variance < 10.0 dB) and localized scotomas (mean defect ≤ 3.0 dB, loss variance ≥ 20.0 dB).
• Intraocular pressure (IOP) and optic disk rim area were measured and compared between the groups.

Main Results:

• Patients with diffuse visual field loss exhibited higher mean peak intraocular pressure (27.6 ± 1.2 mm Hg) compared to those with localized defects (22.4 ± 1.4 mm Hg).
• The localized loss group had a significantly smaller optic disk rim area (1.02 ± 0.15 mm²) than the diffuse loss group (1.33 ± 0.07 mm²), primarily due to thinner temporal rims.
• These findings suggest a correlation between specific visual field defects and structural/physiological differences.

Conclusions:

• Distinct patterns of early visual field loss in POAG may arise from different underlying mechanisms of glaucomatous optic nerve damage.
• Higher IOP is associated with diffuse visual field loss, while localized defects correlate with reduced optic disk rim area.
• Further research is warranted to fully elucidate these divergent pathways.